1. Field of the Invention
The present invention relates to a manufacturing method of a semiconductor device, using a method for etching a conductive film.
2. Description of the Related Art
Practical application of a technology for individual identification by wirelessly transmitting and receiving signals (RFID: radio frequency identification) has been promoted in various fields, and further expansion of the market for application of the technology is expected as a new type of data communication. RF tags are also called ID chips, wireless tags, or IC tags, and each usually have an antenna and an integrated circuit (chip). In the category of RF tags, there are a type having an external-antenna in which an integrated circuit and an antenna which are separately formed are connected and an on-chip type in which an integrated circuit and an antenna are formed over the same substrate.
RF tags tend to increase the communication distance as the resistance of the antenna is decreased, though depending on the impedance of the integrated circuit. In order to decrease the resistance of the antenna, it is important to increase the thickness of a conductive film used for the antenna, in addition to selection of the material of the conductive film.
The formation of the conductive film having a predetermined shape, such as a wiring, an electrode, or an antenna is carried out generally by a droplet discharge method such as an ink-jet method, plating method, etching method (including pattering process), or the like. Among these methods, the etching method is advantageous in that there are few limitations on selecting materials used for the conductive film and a high-definition pattern can be formed. In Japanese Published Patent Application No. 2004-79582, an etching method by which a stack wiring layer including an aluminum alloy layer with a thickness of 3 μm or more is formed to be a predetermined pattern is disclosed.